Prerequisites for the formation of gold spreads on the Ukrainian Shield and on its southern framing

Abstract

The presence of numerous native gold deposits of the Ukrainian Crystalline Shield (UCS), as well as the spread of placer gold manifestations, determines the high probability of the formation of precious metal placers with industrial parameters here. The main factors and geological conditions that contribute to the formation of gold placers are manifested in the UCS. An important reason for the failures of previous geological works is the outdated scientific and methodological platform, which involved the search for typical gold-bearing deposits with metal of gravity classes of size. The possibility of significant movement of placer gold in the clayey water flow and the formation of long-distance placers was not taken into account. The traditional slack method used in the study did not make it possible to determine the actual gold content when particles with a size smaller than 0.25 mm predominate in the sample, which is precisely the particle size of the primary sources of the UCS. The applied means of research could not be effective in the absence of the necessary analytical base for determining the gold content, modern methods of studying the geological structure and tectonics of the territories. The negative results did not provide any real grounds for further specialized large-scale research and prospecting for placer gold. Today, it is becoming obvious that placer gold of small and fine grades can easily move over considerable distances in the water flow and form accumulations not only in boulder-pebble material, but also in pelite sediments. As a result of repeated changes in the tectonic plan of block movements, gold-bearing accumulations could be eroded and redeposited in secondary reservoirs. In this aspect, neotectonic studies (using materials from space surveys) become the main predictive and prospecting method for identifying promising areas of placer gold concentration in the region. Field work should be carried out using drilling and modern methods of laboratory analysis of samples for gold. The results of many years of research give hope for the discovery of real placer gold deposits in the Northern Black Sea region in the near future.